Distributed Usage Control

AbstractWith more and more personal data being collected and stored by service providers, there is an increasing need to ensure that their usage is compliant with privacy regulations and user preferences. We consider the specific scenario where promised usage is specified as metric temporal logic policies, and these policies can be verified against the database usage logs. Given the vast amount of data being collected, scalability is very important. In this work, we show how such usage monitoring can be performed in a distributed fashion for an expressive set of policies. Experimental results are given for a real-life use case to show the genericness and scalability of the results

Privacy Panel: Usable and Quantifiable Mobile Privacy

The ever increasing popularity of apps stems from their ability to provide highly customized services to the user. The flip side is that in order to provide such services, apps need access to very sensitive private information about the user. This leads to malicious apps that collect personal user information in the background and exploit it in various ways. Studies have shown that current app vetting processes which are mainly restricted to install time verification mechanisms are incapable of detecting and preventing such attacks. We argue that the missing fundamental aspect here is a comprehensive and usable mobile privacy solution, one that not only protects the user's location information, but also other equally sensitive user data such as the user's contacts and documents. A solution that is usable by the average user who does not understand or care about the low level technical details. To bridge this gap, we propose privacy metrics that quantify low-level app accesses in terms of privacy impact and transforms them to high-level user understandable ratings. We also provide the design and architecture of our Privacy Panel app that represents the computed ratings in a graphical user-friendly format and allows the user to define policies based on them. Finally, experimental results are given to validate the scalability of the proposed solution

PREVALENCE OF ANTI-HCV, HBSAG, HIV AMONG MULTI-TRANSFUSED THALASSEMIC INDIVIDUALS AND THEIR SOCIO-ECONOMIC BACKGROUND IN EASTERN INDIA

Objective: The objective was to study the serological prevalence of post-transfusion transmitted infections such as hepatitis C virus (HCV), hepatitisB virus (HBV), and HIV among multi-transfused thalassemic individuals of the Eastern India and the socio and financial difficulties faced by them.Methods: The study was carried out from January 2012 until December 2014 involving 1711 thalassemic major individuals. Blood serum wascollected from each patient to perform ELISA for the detection of HBV and HCV seroprevalence. HIV seropositivity along with their hematological andliver function parameters were obtained from the transfusion centers and the host institutions. Other socio-economic conditions were obtained bypredesigned proforma of the questionnaire.Results: 67.9% males and 32.1% females were present in our study population of which 75% were from rural area. The mean hemoglobin was foundto be lower, whereas mean ferritin, bilirubin, and liver enzymes were much higher than the normal range. Only a handful of 19.76% of the fathers ofthalassemic individuals had secondary education. 263 families (15.37%) were familiar with the chances of transfusion-transmitted infections (TTIs).The dominant TTI found within the population was HCV with 18.70% prevalence followed by HIV (3.74%) and HBV (3.33%). 82.93% of the affectedfamilies suffered poverty with a meager monthly income within Rs. 5000 fighting against high costs of transfusion and related treatments.Conclusion: Our study reflects the different socio-economic and psychological burdens faced by the thalassemia patients and their families. The highrate of TTIs highlights the need for stringent screening of blood or blood products before administration.Keywords: Thalassemia, Socio-economic, Transfusion-transmitted infections, Hepatitis C virus, Hepatitis B virus, HIV

Hierarchical Web Services Compositions: Visibility, Compensation and Monitoring

Industry and researchers acknowledge Web services as being at the heart of next generation distributed systems. The most promising feature of the Web services platform is its ability to form new services by combining the capabilities of already existing services, i.e., its composability. The existing services may themselves be composed of other services, leading to a hierarchical composition. In this work, we focus on the visibility, compensation and monitoring aspects for hierarchical compositions. Most works on mechanisms to provide extended functionalities like transactions, monitoring, security, etc. for Web services compositions consider single-level compositions with an implicit assumption that they can be straightforwardly extended to hierarchical compositions. As such, they fail to appreciate an important and unique aspect of hierarchical compositions, the visibility aspect. For example, a service provider may not be aware of any providers in the hierarchy other than its parent and children. On the other hand, a service provider may be aware of all other providers in the hierarchy. Towards this end, we introduce the notion of Spheres of Visibility (SoV). Basically, SoV provides an abstraction to captur

Visibility in hierarchical systems

Les modèles hiérarchiques fournissent un élégant mécanisme d'analyse à différents niveaux d'abstraction. Ils sont habituellement construits dans une approche top-down ou bottom-up, niveau par niveau. En conséquence, par construction, la visibilité des entités dans un système hiérarchique est limitée aux niveaux adjacents (parent-enfant). Cette visibilité n'est souvent pas suffisante pour modèliser tous les scenarios de la vie réelle. D'autre part, une interaction arbitraire, sans aucune restriction, n'est pas une solution acceptable, en raison souvent de préoccupations en matière de sécurité. Dans cette thèse, nous nous adressons à deux sous-problèmes de la visibilité de systèmes hiérarchiques. Tout d'abord, nous considérons le problème de la définition d'un modèle de visibilité, compte tenu des exigences et des restrictions des différentes entités dans une hiérarchie. Nous présentons des modèles de visibilité à base de graphes pour deux types de systèmes hiérarchiques: les Communautés P2P et les services Web compositionnels. Deuxièmement, nous nous intéressons au problème orthogonal de déterminer la visibilité dans la hiérarchie pour qu'une propriété particulière soit satisfaite. Nous donnons des algorithmes pour calculer la visibilité minimale requise pour une hiérarchie de services Web compositionnels afin de fournir la propriété de l'atomicité des opérations. Cette visibilité minimale est calculée à la fois de manière absolue et de manière approchée.Hierarchical systems provide an elegant mechanism to analyze system functionality at different levels of abstraction. They are usually constructed in a top-down or bottom-up fashion level by level. As a result, by construction, visibility of entities in a hierarchical system is restricted to adjacent (parent-child) levels. Such restricted visibility is often not sufficient for real-life scenarios. On the other hand, allowing arbitrary interaction among the hierarchical entities, without any restrictions, is not an acceptable solution either due to security concerns. In this thesis, we address two sub-problems of the visibility issue in hierarchical systems. First, we consider the problem of defining a visibility model, given the visibility requirements and restrictions of the different entities in a hierarchy. We present graph based visibility models for two specific hierarchical systems: P2P Communities and Web services compositions. Second, we deal with the orthogonal problem of determining the visibility requirements of the given hierarchy such that a specific property holds. We give both absolute and approximate algorithms to determine the minimal visibility required by a hierarchical Web services composition to provide the property of transactional atomicity.RENNES1-BU Sciences Philo (352382102) / SudocRENNES-INRIA Rennes Irisa (352382340) / SudocSudocFranceF

Formalizing Visibility Characteristics in Hierarchical Systems

We consider hierarchical systems where nodes represent entities and edges represent binary relationships among them. An example is a hierarchical composition of Web services where the nodes denote services and edges represent the parent-child relationship of a service invoking another service. A fundamental issue to address in such systems is, for two nodes X and Y in the hierarchy whether X can see Y , that is, whether X has visibility over Y . In a general setting, X seeing Y may depend on (i) X wishing to see Y , (ii) Y wishing to be seen by X, and (iii) other nodes not objecting to X seeing Y . The visibility could be with respect to certain attributes like operational details, execution logs, security related issues, etc. In this paper, we develop a generic conceptual model to express visibility. We study two complementary notions: sphere of visibility of a node X that includes all the nodes in the hierarchy that X can see; and sphere of noticeability of X that includes all the nodes that can see X. We also identify dual properties, coherence and correlation, that relate the visibility and noticeability notions, and study their variants

Minimal Observability and Privacy Preserving Compensation for Transactional Services

International audienceFor complex services composed of many (component) services, logging is an integral middleware aspect, especially for providing transactions and monitoring. In the event of a failure, the log allows us to deduce the cause of failure (diagnosis) and recover by compensating the executed services (atomicity). However, for heterogeneous services with parts of the functionality provided by multiple organizations, logging details of all executed services is often impracticable due to privacy/security constraints. Also, logging is expensive in terms of both time and space. Thus, we are interested in determining the minimal number of services that need to be logged, and which is still sufficient to know with certainty the actual sequence of executed services from any given log. Further to privacy issues, the complexity of determining a minimal set of such services to log is actually NP-Complete. To solve {\em both issues}, we resort to considering each component service as a grey box. Logs are recorded and kept local to each component, and a black-box view of the implementation details of each component is provided. In particular, a service which is reused as a component several times (often observed in real-life services) need not be re-computed each time. We show that this dramatically decreases the complexity up to 2 exponentials. For large monolithic component services that cannot be decomposed simply, we also provide heuristics to compute a small (but not necessarily minimal) number of services to log, and experimentally analyze their accuracy and performance

Atomicity for P2P based XML Repositories

Over the years, the notion of transactions has become synonymous with providing fault-tolerance, reliability and robustness to database systems. However, challenges arise when we try to apply them to novel computing paradigms such as ActiveXML (AXML) systems. AXML provides an elegant platform to integrate the power of XML, Web services and Peer to Peer (P2P) paradigms by allowing (active) Web services calls to be embedded within XML documents. We propose a transactional framework which provides relaxed ACID properties to AXML systems. Relaxed atomicity is usually provided with the help of compensation. However, current compensation based models assume the existence of a pre-defined compensating operation. Also, compensation is assumed to be more or less peer (or service provider) dependent, i.e., the original and compensating services are provided by the same peer. We show how compensation for AXML transactions can be constructed dynamically at run-time and achieved in a peer independent manner. Finally, we consider the issue of peer disconnection, an inherent trait of P2P systems, and propose an innovative solution based on peer “chaining”. 1